Docker Engine v29 on Linux: Why data-root No Longer Prevents OS Disk Growth (and How to Fix It)

Good write-up. For Azure VMs, I would also call out that moving Docker's data-root is only one part of the disk-growth story.

I normally check three separate paths: Docker/container data, journald/syslog growth, and anything still writing under /var/lib or /var/log. Even after moving image and layer storage to a data disk, logs, container runtime metadata, temp files, and package/cache activity can still pressure the OS disk.

A safer pattern is to mount a dedicated managed data disk, move the heavy container paths there, add log rotation limits, and monitor OS disk free space separately from the Docker data disk. That way a noisy container does not silently turn into a VM availability problem.